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Android Build a Simple Android App Improving Our Code Using the New Colors

Posted by Arthur Kharzamanov
Arthur Kharzamanov
5,414 Points

I am a bit confused when we need to declare a private member variable and when to create a new object;

Hello everyone,

So now that I made a mistake of just creating a private member variable mColorWheel of type ColorWheel and calling getColor method with that variable which caused a runtime error: NullPointerException : Attempt to invoke virtual method 'java.lang.String com.example.akboss.funfacts.FactBook.getFact()' on a null object reference.

I am a little confused about when object creation is required.

Why was it so crucial to create a new ColorWheel object and to then use it to call the getColor() method? I know I learned this in the Java course and it should be simple yet once I put it to practice I got confused.

If someone could explain to me the reason for the NullPointerException I got and why an new object must have been created, I would appreciate it.

Thank you!